Multi-pipe three-dimensional plusating heat pipe

ABSTRACT

A multi-pipe three-dimensional pulsating heat pipe includes at least two pipes and at least two chambers. The at least two pipes form into respective three-dimensional annular loops. A cooling zone is formed to one side of the annular loops. Two opposing ends of the at least two pipes are connected spatially to the at least two chambers, respectively, so as to form the multi-pipe three dimensions pulsating heat pipe.

CROSS REFERENCE TO RELATED APPLICATION

The present application is based on, and claims priority from, Taiwan (International) Application Serial Number 105121605, filed on Jul. 7, 2016, the disclosure of which is hereby incorporated by reference herein in its entirety.

TECHNICAL FIELD

The present disclosure relates to a heat pipe for heat dissipation, and more particularly to a multi-pipe three-dimensional pulsating heat pipe that is structured by a 3D (three-dimensional) stacking arrangement.

BACKGROUND

The heat pipe is well known to have excellent thermal characterization, and thus is widely applied to heat-dissipate electronic elements, particularly personal computers and notebook computers. Generally, while in encountering a heat-dissipation need for a plane heat source, it is as usual to implement a plurality of heat pipes to meet the heat-dissipation need. However, the design for applying multiple heat pipes at the same time would cause manufacturing and assembling difficulty in heat-dissipation modules. Hence, while in meeting a requirement for heat-dissipating a plane heat source, the planar heat pipe or the vapor chamber would be more appropriate than the conventional heat pipe.

In the art, a conventional pulsating heat pipe is generally a heat-dissipation member consisted of several bent pipes. A two-phase flow pulsation phenomenon in the heat pipe is produced by an in-pipe pressure difference caused by the heated work fluid of the heat pipe. Such a phenomenon can push the work fluid to flow back to the evaporation end of the heat pipe without a capillary structure. By implementing this pulsation phenomenon, air bubbles and the fluid segments in heat pipe can be easily and automatically driven to form an in-pipe circulation, such that heat at or outside one specific portion of the heat pipe can be conveyed distantly to be dissipated through another portion of the same heat pipe. It is important that such a technique in heat piping does not require a capillary structure, and thus the manufacturing cost can be reduced effectively. Hence, the pulsation technique in heat piping is much more appropriate to be applied to a product with mass heat transfer amount and an extended transfer range. However, the pulsating heat pipe does have a structural limitation in the radius of curvature for the bent pipes, by which the manufacturing difficulty is increased. As a tiny radius of curvature is met, the pipe is vulnerable to be over deformed or evenly fractured. Thus, the application of this pulsation technique is still limited. In addition, the production of the bent pipes requires additional specific tooling for the bending task, and thus an increase of cost in manufacturing the heat pipe with bent piping would be inevitable.

In addition, after necessary bending upon the pipes, invalid areas (or invalid zones) would be formed in theses bent pipes, by which the transferable heat amount per unit projection area (W/cm²) would be substantially reduced. Consequently, the heat flux would be deficit, the thermal resistance would be hike, and additional unexpected inconvenience in both design and development would be met.

SUMMARY

Accordingly, it is the object of the present disclosure to provide a multi-pipe three-dimensional pulsating heat pipe that the performance can be enhanced, the manufacturing can be convenient, and the production cost can be reduced.

In this disclosure, the multi-pipe three-dimensional pulsating heat pipe includes at least two pipes and at least two chambers. Each of the at least two pipes is formed into repeated three-dimensional annular loops, and at least one side of the annular loops is defined as a cooling area. The at least two chambers connect respectively and spatially to two opposing ends of each of the at least two pipes so as to form the multi-pipe three-dimensional pulsating heat pipe.

By providing the multi-pipe three-dimensional pulsating heat pipe of this disclosure, at least two opposing ends of the pipes are installed with individual chambers for bifurcating and refilling the work fluid, and also the annular loops produced according to the 3D stacking pattern would prevent the multi-pipe three-dimensional pulsating heat pipe from the influence of bending and curving upon the pipes. With the cooling area to be formed at one side of the annular loops at least according to the tight stacking, no invalid area would be produced to degrade the heat transfer. Thereupon, when the cooling area of the multi-pipe three-dimensional pulsating heat pipe is adhered to the evaporation zone, a close face-to-face heat transfer pattern can be established to significantly enhance the heat flux.

In addition, while in manufacturing the multi-pipe three-dimensional pulsating heat pipe of this disclosure, no further bending tool or jig as required in the conventional design is needed, such that the manufacturing can be efficiency and the production cost can be reduced.

Further scope of applicability of the present application will become more apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating exemplary embodiments of the disclosure, are given by way of illustration only, since various changes and modifications within the spirit and scope of the disclosure will become apparent to those skilled in the art from this detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure will become more fully understood from the detailed description given herein below and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present disclosure and wherein:

FIG. 1 is a schematic perspective view of a first embodiment of the multi-pipe three-dimensional pulsating heat pipe in accordance with this disclosure;

FIG. 2 shows a portion of the annular loops at a side of the multi-pipe three-dimensional pulsating heat pipe of FIG. 1;

FIG. 3 is a schematic left-hand-side view of FIG. 1;

FIG. 4 is a schematic view of a second embodiment of the multi-pipe three-dimensional pulsating heat pipe in accordance with this disclosure;

FIG. 5 is a schematic view of a third embodiment of the multi-pipe three-dimensional pulsating heat pipe in accordance with this disclosure;

FIG. 6 is a schematic view of a fourth embodiment of the multi-pipe three-dimensional pulsating heat pipe in accordance with this disclosure;

FIG. 7 is a schematic view of a fifth embodiment of the multi-pipe three-dimensional pulsating heat pipe in accordance with this disclosure;

FIG. 8 is a schematic view of a sixth embodiment of the multi-pipe three-dimensional pulsating heat pipe in accordance with this disclosure;

FIG. 9 is a schematic view of a seventh embodiment of the multi-pipe three-dimensional pulsating heat pipe in accordance with this disclosure; and

FIG. 10 is a schematic view of an eighth embodiment of the multi-pipe three-dimensional pulsating heat pipe in accordance with this disclosure.

DETAILED DESCRIPTION

In the following detailed description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the disclosed embodiments. It will be apparent, however, that one or more embodiments may be practiced without these specific details. In other instances, well-known structures and devices are schematically shown in order to simplify the drawing.

Refer now to FIG. 1 and FIG. 2; where FIG. 1 is a schematic perspective view of a first embodiment of the multi-pipe three-dimensional pulsating heat pipe in accordance with this disclosure, and FIG. 2 shows a portion of the annular loops at a side of the multi-pipe three-dimensional pulsating heat pipe of FIG. 1. It shall be explained firstly, so as helpful to conveniently elucidate the present disclosure lately, that, in FIG. 1, an orthogonal X-Y-Z coordinate system is defined, in which the first axis is the axis X extending in an X-axial direction, the second axis is the axis Y extending in a Y-axial direction, and the third axis is the axis Z extending in a Z-axial direction.

In this disclosure, the multi-pipe three-dimensional pulsating heat pipe 100 includes at least two pipes and at least two chambers 120.

Referring to the first embodiment of FIG. 1, the multi-pipe three-dimensional pulsating heat pipe 100 includes a first pipe 112, a second pipe 114, a third pipe 116, and two chambers 120.

The first pipe 112, the second pipe 114 and the third pipe 116 are parallel arranged into a tri-pipe assembly, and this tri-pipe assembly is structured to be repeated annular loops as shown in FIG. 1. The annular loops integrally include an outer-frame portion 110 and a central empty portion 130, in which the outer-frame portion 110 is consisted of a first side A1, a second side A2, a third side A3 and a fourth side A4. The first side A1 and the second side A2 are located to form two opposing horizontal sides of the outer-frame portion 110 in the Y-axial direction, while the third side A3 and the fourth side A4 are located to form two opposing vertical sides of the outer-frame portion 110 in the X-axial direction. Thereupon, the annular loops are formed to be a 3D rectangular frame structure.

Namely, by referring to FIG. 1, in forming the annular loops (i.e. the 3D rectangular frame structure), the first pipe 112, the second pipe 114 and the third pipe 116 are firstly parallel integrated into the tri-pipe assembly. Then, the tri-pipe assembly is bent continuously along a rectangular pattern several times in a collapse or stacking manner so as to form the 3D rectangular frame structure of FIG. 1 having the outer-frame portion 110 (formed by the circling pipes) and the central empty portion 130 (encircled by the circling pipes). As shown, in particular, the first side A1 of the outer-frame portion 110 is located on a lower X-Z plane, the second side A2 of the outer-frame portion 110 is located on an upper X-Z plane opposing to the first side A3 by crossing the central empty portion 130, the third side A3 of the outer-frame portion 110 is located on a Y-Z plane, and the fourth side A4 of the outer-frame portion 110 is located on another Y-Z plane opposing to the third side A3 by crossing the central empty portion 130. By having the aforesaid bending and stacking, the annular loops are then formed into the 3D rectangular frame structure according to the 3D stacking pattern and, particularly in FIG. 1, into a symmetric structure. However, in some other embodiments, the 3D annular loops can be formed into an asymmetric structure or another symmetric structure, specifically according to different practical needs.

The two chambers 120 are the structured to two opposing ends of tri-pipe assembly consisted of the first pipe 112, the second pipe 114 and the third pipe 116 in parallel. By having these two chambers 120, the first pipe 112, the second pipe 114, the third pipe 116, and the two chambers 120 can then be formed to have a connected interior space for the multi-pipe three-dimensional pulsating heat pipe 100 in this disclosure. While in application, this connected interior space can accommodate the work fluid.

In this disclosure, at least one side of the aforesaid annular loops of the multi-pipe three-dimensional pulsating heat pipe 100 is adopted to form a cooling area. As shown in FIG. 2, the first pipe 112, the second pipe 114 and the third pipe 116 located at the first side A1 of the annular loops is tightly integrated to form the cooling area. By having a tightly stacking to eliminate possible invalid area between any two neighboring pipes of the first pipe 112, the second pipe 114 and the third pipe 116, a planar cooling zone can then be formed for a particular heat transfer purpose.

In this embodiment, the aforesaid pipes can be, but not limited to, metallic pipes. In some other embodiments, the pipes can be non-metallic pipes.

In this embodiment, all the aforesaid pipes can have, but not limited to, the same diameter or the same cross-sectional area. However, in some other embodiments, the pipes can have different diameters or different cross-sectional areas.

Referring now to FIG. 3, a schematic left-hand-side view of FIG. 1 is shown. It shall be noted that, in order to have a concise description, some elements in FIG. 1 are now omitted in FIG. 3. For details of these omitted elements, please refer back to FIG. 1 and related description.

In this embodiment, the multi-pipe three-dimensional pulsating heat pipe 100 can construct an evaporation zone 140 and a condensation zone 150 to opposing sides of the heat pipe 100, respectively. For example, in FIG. 3, the evaporation zone 140 of the multi-pipe three-dimensional pulsating heat pipe 100 is located at the first side A1, while the condensation zone 150 of the multi-pipe three-dimensional pulsating heat pipe 100 is located at the second side A2. In another embodiment not shown herein, the condensation zone of the multi-pipe three-dimensional pulsating heat pipe can be located at the first side A1, and the evaporation zone of the multi-pipe three-dimensional pulsating heat pipe is located at the second side A2. In addition, the present disclosure does not limit the chambers 120 to be located in the condensation zone. Actually, in accordance with the present disclosure, the chambers 120 can be located at other places of the multi-pipe three-dimensional pulsating heat pipe 100.

According to the present disclosure, the heating source (not shown in the figure) is located at one side of the outer-frame portion 110. By having FIG. 3 as an example, the heating source is located at the first side A1 of the outer-frame portion 110 (namely the evaporation zone 140), and heat-dissipation fins can be mounted to the second side A2 of the outer-frame portion 110 (namely the condensation zone) for heat dissipation. In the present disclosure, the evaporation zone 140 to receive foreign heat energy is typically assigned to, but not limited to, the first side A1.

The multi-pipe three-dimensional pulsating heat pipe 100 further includes an anchorage member 160 located in the central empty portion 130. Namely, while the outer-frame portion 110 can serve as a supportive frame, the central empty portion 130 can provide an installation space to accommodate the anchorage member 160. In this embodiment, the anchorage member 160 can be a circuit structure, a mechanism, a heat-dissipation member, or any the like.

Upon the aforesaid arrangement, the repeating annular-loop structure, including three parallel pipes and two chambers 120 located respectively to opposing ends of the pipes for bifurcating and also filling the work fluid, can perform annularly circulation and introduce the 3D stacking pattern for producing a tight stacking structure to lessen the effect of bending (that produces small radius of curvature to the pipe) upon the multi-pipe three-dimensional pulsating heat pipe 100. The work fluid (water, methanol, acetone, or any pure liquid or solution the like) is filled into the heat pipe 100 through one of the chambers 120. The work fluid inside the heat pipe 100 is flowed in a cross-flowing manner so as to produce unbalanced flowing, by which the difficulty for the work fluid to flow horizontally in the pulsating heat pipe can be resolved. Also, the heat pipe 100 of this disclosure can be operated in a negative 90-degree state (i.e. with the evaporation zone to be positioned above the condensation zone) so as to help the work fluid to flow back to the evaporation zone without substantial helps from the gravity. Further, heating of the work fluid can be operated no matter if the heat pipe 100 is posed at a horizontal or a negative-angling state.

In addition, for example, by having the first side A1 of the multi-pipe three-dimensional pulsating heat pipe 100 close to the cooling zone (definitely, respective to the heat source) and preferably by having the evaporation zone 140 at the first side A1 of the heat pipe 100 to adhere closely to the cooling zone of the heat source so as not to generate invalid areas in between, the heat flux between the heat pipe 100 and the heat source can be significantly increased.

Further, since the multi-pipe three-dimensional pulsating heat pipe 100 of this disclosure is a symmetric structure, thus, while in manufacturing, the tri-pipe assembly is based on a specific annular pattern to extend continuously and to repeat according to the 3D stacking pattern, such that the annular loops as shown in FIG. 1 for the multi-pipe three-dimensional pulsating heat pipe 100 can be produced. During the manufacturing, no further bending tool or jig as required in the conventional design is needed, such that the manufacturing can be efficiency and the production cost can be reduced.

Referring now to FIG. 4, a schematic view of a second embodiment of the multi-pipe three-dimensional pulsating heat pipe in accordance with this disclosure is illustrated. It shall be noted that the multi-pipe three-dimensional pulsating heat pipe 200 of FIG. 4 is structurally similar to that 100 of FIG. 1 through FIG. 3. Hence, the same elements in between would assigned the same numbers, and details thereabout would be omitted herein. Following description upon this second embodiment of FIG. 4 would be focused on the differences between this second embodiment and the first embodiment of FIG. 1 through FIG. 3.

As shown in FIG. 4, the annular loop for each pipe is shaped to be a triangle, and the whole annular loops include an outer-frame portion 210 and a central empty portion 230, in which the outer-frame portion 210 is consisted of a first side B1, a second side B2 and a third side B3. In particular, the first side B1 of the annular loops is defined as a cooling area. Similar to the aforesaid 3D stacking pattern, the annular loops of this second embodiment are formed to be a 3D triangular structure.

In the second embodiment 200 of the multi-pipe three-dimensional pulsating heat pipe, the first side B1 defines an evaporation zone 240, and both the second side B2 and the third side B3 define individual condensation zones 252, 254, respectively.

Referring now to FIG. 5, a schematic view of a third embodiment of the multi-pipe three-dimensional pulsating heat pipe in accordance with this disclosure is shown. It shall be noted that the multi-pipe three-dimensional pulsating heat pipe 300 of FIG. 5 is structurally similar to that 100 of FIG. 1 through FIG. 3. Hence, the same elements in between would assigned the same numbers, and details thereabout would be omitted herein. Following description upon this third embodiment of FIG. 5 would be focused on the differences between this third embodiment and the first embodiment of FIG. 1 through FIG. 3.

As shown in FIG. 5, the annular loop for each pipe is shaped to be a trapezoid, and the whole annular loops include an outer-frame portion 310 and a central empty portion 330, in which the outer-frame portion 310 is consisted of a first side C1, a second side C2, a third side C3 and a fourth side C4, and the first side C1. The second side C2 are the vertical-directional opposing sides of the outer-frame portion 310, and a length of the second side C2 is larger than that of the first side C1. The third side C3 and the fourth side C4 are the horizontal-directional opposing sides of the outer-frame portion 310. The first side C1 of the annular loops is defined as a cooling area. Similar to the aforesaid 3D stacking pattern, the annular loops of this third embodiment are formed to be a 3D trapezoidal structure.

In the third embodiment 300 of the multi-pipe three-dimensional pulsating heat pipe, the first side C1 defines an evaporation zone 340, and the second side C2 defines a condensation zone 350.

As described above, the 3D stacking pattern of this disclosure is not limited to form a 3D rectangular structure as shown in FIG. 3. The 3D triangular structure (FIG. 4) and the 3D trapezoidal structure (FIG. 5) are also exemplary embodiments for the 3D stacking pattern of the present disclosure. In practice, the shape of the annular loops is determined mainly according to practical demands.

Referring now to FIG. 6, a schematic view of a fourth embodiment of the multi-pipe three-dimensional pulsating heat pipe in accordance with this disclosure is illustrated. It shall be noted that the multi-pipe three-dimensional pulsating heat pipe 400 of FIG. 6 is structurally similar to that 100 of FIG. 1 through FIG. 3. Hence, the same elements in between would assigned the same numbers, and details thereabout would be omitted herein. Following description upon this fourth embodiment of FIG. 6 would be focused on the differences between this fourth embodiment and the first embodiment of FIG. 1 through FIG. 3.

As shown in FIG. 6, the third side A3 of the annular loops is defined as a cooling area. A lower portion of the third side A3 of the multi-pipe three-dimensional pulsating heat pipe 400 defines an evaporation zone 440. The fourth side A4 of the multi-pipe three-dimensional pulsating heat pipe 400 defines a condensation zone 450. Compared with the aforesaid embodiments of FIG. 1 through FIG. 5 that all have the heating sources (evaporation zones) to be located at the corresponding bottom sides, the heating source of FIG. 6 is located at the lateral side and has the evaporation zone 440 to be located lower than the condensation zone 450.

Referring now to FIG. 7, a schematic view of a fifth embodiment of the multi-pipe three-dimensional pulsating heat pipe in accordance with this disclosure is illustrated. It shall be noted that the multi-pipe three-dimensional pulsating heat pipe 500 of FIG. 7 is structurally similar to that 100 of FIG. 1 through FIG. 3. Hence, the same elements in between would assigned the same numbers, and details thereabout would be omitted herein. Following description upon this fifth embodiment of FIG. 7 would be focused on the differences between this fifth embodiment and the first embodiment of FIG. 1 through FIG. 3.

As shown in FIG. 7, the second side A2 of the annular loops is defined as a cooling area. A middle portion of the second side A2 of the multi-pipe three-dimensional pulsating heat pipe 500 defines an evaporation zone 540. The first side A1 of the multi-pipe three-dimensional pulsating heat pipe 500 defines a condensation zone 550. Compare with the aforesaid embodiments, the embodiment of FIG. 7 demonstrates an application of heating in an anti-gravity manner. Namely, in this embodiment, the evaporation zone 540 is located above the condensation zone 550, i.e. operated in a negative 90-degree state. Even without the gravity to flow the work fluid back to the evaporation zone, the heat pipe 500 of this embodiment can still work.

Referring now to FIG. 8, a schematic view of a sixth embodiment of the multi-pipe three-dimensional pulsating heat pipe in accordance with this disclosure is illustrated. It shall be noted that the multi-pipe three-dimensional pulsating heat pipe 600 of FIG. 8 is structurally similar to that 100 of FIG. 1 through FIG. 3. Hence, the same elements in between would assigned the same numbers, and details thereabout would be omitted herein. Following description upon this sixth embodiment of FIG. 8 would be focused on the differences between this sixth embodiment and the first embodiment of FIG. 1 through FIG. 3.

As shown in FIG. 8, the second side A2 of the annular loops is defined as a cooling area. An upper portion of the third side A3 of the multi-pipe three-dimensional pulsating heat pipe 600 defines an evaporation zone 640. A lower portion of the fourth side A4 of the multi-pipe three-dimensional pulsating heat pipe 600 defines a condensation zone 650. In the embodiment of FIG. 8, except for arranging the lateral side (A3) to receive the heat, the application of heating in an anti-gravity manner is also utilized in this embodiment. Namely, the evaporation zone 640 is located above the condensation zone 650.

Hence, in the present disclosure, the evaporation zone is not necessary to position at the bottom side of the heat pipe, and, alternatively per practical demands, the lateral-side heating, the anti-gravity heating or a combination of the aforesaid heating is also a possible option.

Referring now to FIG. 9, a schematic view of a seventh embodiment of the multi-pipe three-dimensional pulsating heat pipe in accordance with this disclosure is illustrated. It shall be noted that the multi-pipe three-dimensional pulsating heat pipe 700 of FIG. 9 is structurally similar to that 100 of FIG. 1 through FIG. 3. Hence, the same elements in between would assigned the same numbers, and details thereabout would be omitted herein. Following description upon this seventh embodiment of FIG. 9 would be focused on the differences between this seventh embodiment and the first embodiment of FIG. 1 through FIG. 3.

Referring to FIG. 9, the multi-pipe three-dimensional pulsating heat pipe 700 is structured to be a dual-layer heat-transferring module. The annular loops include two outer-frame portions 110 and 770. The larger-size outer-frame portion 110 located outside thereof sleeves the smaller-size outer-frame portion 770, preferably by a predetermined spacing. Inside the smaller-size outer-frame portion 770, a central empty portion 730 of the annular loops is located.

In this embodiment, the evaporation zone 740 of the multi-pipe three-dimensional pulsating heat pipe 700 is located at a lower portion thereof between a bottom side of the larger-size outer-frame portion 110 and a bottom side of the smaller-size outer-frame portion 770. The condensation zone 750 is defined at the second side A2 of the multi-pipe three-dimensional pulsating heat pipe 700. Hence, the heating source within the evaporation zone 740 can have both sides to dissipate heat to the lower larger-size outer-frame portion 110 and the upper smaller-size outer-frame portion 740.

Referring now to FIG. 10, a schematic view of an eighth embodiment of the multi-pipe three-dimensional pulsating heat pipe in accordance with this disclosure is illustrated. It shall be noted that the multi-pipe three-dimensional pulsating heat pipe 800 of FIG. 10 is structurally similar to that 700 of FIG. 9. Hence, the same elements in between would assigned the same numbers, and details thereabout would be omitted herein. Following description upon this eighth embodiment of FIG. 10 would be focused on the differences between this eighth embodiment and the seventh embodiment of FIG. 9

In FIG. 10, the multi-pipe three-dimensional pulsating heat pipe 800 also has a dual-layer heat-transferring module. Namely, the annular loops include two outer-frame portions 110 and 870. The larger-size outer-frame portion 110 located outside thereof sleeves the smaller-size outer-frame portion 870, preferably by a predetermined spacing. Inside the smaller-size outer-frame portion 870, a central empty portion 830 of the annular loops is located.

In this embodiment, the evaporation zone 840 of the multi-pipe three-dimensional pulsating heat pipe 800 is located at a first side A1, while the condensation zone 850 is defined at a second side A2 of the multi-pipe three-dimensional pulsating heat pipe 800.

Upon such an arrangement of the eighth embodiment, the larger-size outer-frame portion 110 can contain a first work fluid, while the smaller-size outer-frame portion 870 can contain a second work fluid. In particular, the first work fluid is different to the second work fluid. Namely, these two work fluids have different work temperature. For example, if the work fluid is the water, then the heat pipe would initiate the evaporation of the work fluid (in a comparative high-temperature region) while the work pressure is 0.3 atmosphere and the temperature reaches 69° C. Also, at this time, driving forces inside the heat pipe is sufficient to circulate the work fluid. For another example, if the work fluid is the acetone, then the heat pipe would initiate the evaporation of the work fluid (in a comparative low-temperature region) while the work pressure is 0.3 atmosphere and the temperature reaches 37° C. Thus, by applying different work fluids, this embodiment of the multi-pipe three-dimensional pulsating heat pipe 800, formed as a dual-layer heat-transferring module, can provide two annular loops (the larger-size outer-frame portion aa0 and the smaller-size outer-frame portion 870) to handle the comparative high-temperature region and the comparative low-temperature region, respectively.

Following Table 1 lists comparisons of testing between the conventional pulsating heat pipe and the multi-pipe three-dimensional pulsating heat pipe of this disclosure.

TABLE 1 Test results of the conventional pulsating heat pipe and the multi- pipe three-dimensional pulsating heat pipe of this disclosure Present multi-pipe three- Conventional pulsating heat dimensional pulsating heat pipe pipe Filling amount 21 ml 36 ml Operation 90 degrees 90 degrees angle Heating power 300 W 1000 W Average 100° C. 92° C. temperature of evaporation zone Area of 75 cm²(25 × 3) 30 cm²(5 × 6) evaporation zone Heat- 30 cm 35 cm transferring distance Heat flux 4 W/cm² 33.3 W/cm² Volume filling 30% ± 5% 37% ± 5% ratio

In Table 1, the heat flux of the conventional pulsating heat pipe is 4 W/cm², while the heat flux of the multi-pipe three-dimensional pulsating heat pipe of this disclosure is 33.3 W/cm². Namely, experimentally, the heat flux of the instant multi-pipe three-dimensional pulsating heat pipe is 8 times of that of the conventional pulsating heat pipe. Obviously, by introducing the multi-pipe three-dimensional pulsating heat pipe of this disclosure, the heat flux can be significantly enhanced.

Since the conventional pulsating heat pipe includes a plurality of pipes, and each of these pipes is bent to form an individual ophidian loop. In addition, each of the individual ophidian loops is circularly formed to be an independent and sealed system. However, due to the limitation of the bent pipe in curvature, spacing between pipes is inevitable. Thus, when the conventional pulsating heat pipe is adhered to the heating source, the spacing between neighboring pipes would generate plenty of invalid areas for heat transfer. On the other hand, the multi-pipe three-dimensional pulsating heat pipe of this disclosure introduces the 3D stacking pattern to waive the effect of curvatures upon the piping, so that a tight stacking structure can be produced to have the cooling area formed at one lateral side, at least, of the annular loops not to generate an invalid area. Upon such an arrangement, a close face-to-face heat transfer pattern can be established to significantly enhance the heat flux.

In summary, by providing the multi-pipe three-dimensional pulsating heat pipe of this disclosure, at least two opposing ends of the pipes are installed with individual chambers for bifurcating and refilling the work fluid, and also the annular loops produced according to the 3D stacking pattern would prevent the multi-pipe three-dimensional pulsating heat pipe from the influence of bending and curving upon the pipes. With the cooling area to be formed at one side of the annular loops at least according to the tight stacking, no invalid area would be produced to degrade the heat transfer. Thereupon, when the cooling area of the multi-pipe three-dimensional pulsating heat pipe is adhered to the evaporation zone, a close face-to-face heat transfer pattern can be established to significantly enhance the heat flux.

Also, the work fluid (water, methanol, acetone, or any pure liquid or solution the like) is filled into the heat pipe through one of the chambers. In the heat pipe, due to unbalanced capillary forcing upon the work fluid, gas/liquid segments of the work fluid would be produced and arbitrarily distributed inside the pipes. In particular, opposing ends of the liquid segment may sustain different forcing, through which the gas segment would push the neighboring liquid segment to move and so as to generate the pulsation and circulation of the gas/liquid segments. By having the latent heat transfer at phase changing and the sensible heat transfer at liquid pulsation, the work fluid can flow in a cross-flowing manner so as to produce unbalanced flowing, by which the difficulty for the work fluid to flow horizontally in the pulsating heat pipe can be resolved. Also, the heat pipe of this disclosure can be operated in a negative 90-degree state (i.e. with the evaporation zone to be positioned above the condensation zone) so as to help the work fluid to flow back to the evaporation zone without substantial helps from the gravity. Further, heating of the work fluid can be operated no matter whether the heat pipe is posed at a horizontal or a negative-angling state.

In addition, since the multi-pipe three-dimensional pulsating heat pipe of this disclosure is a symmetric structure, thus, while in manufacturing, the tri-pipe assembly is based on a specific annular pattern to extend continuously and to repeat according to the 3D stacking pattern, such that the annular loops for the multi-pipe three-dimensional pulsating heat pipe of this disclosure can be produced. During the manufacturing, no further bending tool or jig as required in the conventional design is needed, such that the manufacturing can be efficiency and the production cost can be reduced.

Further, since the pipes of the multi-pipe three-dimensional pulsating heat pipe are all formed to be annular loops, the outer-frame portion can serve as supportive frame, while the central empty portion can accommodate an anchorage member such as a circuit structure, a mechanism, a heat-dissipation member, or any the like. In particular, according to the practical need in accommodating the anchorage member, the size or dimension of the annular loops can be relevantly adjusted. Thus, the multi-pipe three-dimensional pulsating heat pipe in accordance with the present disclosure can serve both a heat pipe and a supportive frame.

Furthermore, except for an application in dissipating the insulated gate bipolar transistor (IGBT), the multi-pipe three-dimensional pulsating heat pipe in accordance with the present disclosure can also be used to dissipate a CPU, a COB (Chip on board) LED, a server, a data center, an industrial recycling of exhaust heat or any other high-power density field the like. In addition, while in application, a modularization design can be adopted to the annular loops, so that the multi-pipe three-dimensional pulsating heat pipe can suit for various sizes of the objects to be heat-dissipated.

In addition, to meet a high-power heating source, the aforesaid dual-layer heat-transferring module can be applied to have both sides of the heating source to be heat-dissipated simultaneously within the evaporation zone of the multi-pipe three-dimensional pulsating heat pipe of this disclosure, such that better heat transfer performance can be achieved.

With respect to the above description then, it is to be realized that the optimum dimensional relationships for the parts of the disclosure, to include variations in size, materials, shape, form, function and manner of operation, assembly and use, are deemed readily apparent and obvious to one skilled in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present disclosure. 

What is claimed is:
 1. A multi-pipe three-dimensional pulsating heat pipe, comprising: at least two pipes, each of the at least two pipes being formed into three-dimensional annular loops, at least one side of the annular loops being defined as a cooling area; and at least two chambers, connecting respectively and spatially to two opposing ends of each of the at least two pipes so as to form the multi-pipe three-dimensional pulsating heat pipe.
 2. The multi-pipe three-dimensional pulsating heat pipe of claim 1, wherein each of the at least two pipes is a metallic pipe or a non-metallic pipe.
 3. The multi-pipe three-dimensional pulsating heat pipe of claim 1, wherein the three-dimensional annular loops are symmetric structures or asymmetric structures.
 4. The multi-pipe three-dimensional pulsating heat pipe of claim 1, wherein the at least two pipes have the same diameter or cross-sectional area.
 5. The multi-pipe three-dimensional pulsating heat pipe of claim 1, wherein the at least two pipes have different diameters or cross-sectional areas.
 6. The multi-pipe three-dimensional pulsating heat pipe of claim 1, wherein the three-dimensional annular loops include an outer-frame portion and a central empty portion.
 7. The multi-pipe three-dimensional pulsating heat pipe of claim 6, further including a heating source located at one side of the outer-frame portion.
 8. The multi-pipe three-dimensional pulsating heat pipe of claim 6, further including an anchorage member located in the central empty portion.
 9. The multi-pipe three-dimensional pulsating heat pipe of claim 8, wherein the anchorage member is one of a circuit, a mechanism and a heat-dissipation member.
 10. The multi-pipe three-dimensional pulsating heat pipe of claim 1, wherein each of the at least two pipes is filled with a work fluid; wherein, while the work fluid is heated, the multi-pipe three-dimensional pulsating heat pipe is operable in a horizontal or a negative-angling state.
 11. The multi-pipe three-dimensional pulsating heat pipe of claim 1, wherein one side of the annular loops is defined as an evaporation zone, while another side of the annular loops is defined as a condensation zone.
 12. The multi-pipe three-dimensional pulsating heat pipe of claim 1, wherein the annular loops are rectangular, trapezoidal or triangular shaped. 